Aradus macrosomus, Heiss, 2014

Heiss, Ernst, 2014, Revision of the flat bug family Aradidae from Baltic Amber IX. Aradus macrosomus sp. n. (Hemiptera: Heteroptera), Deutsche Entomologische Zeitschrift 61 (1), pp. 27-29 : 27

Aradus macrosomus sp. n. Figs 1-4

Material examined.

Holotype female in a honey-coloured transparent piece of Baltic Amber, which will be embedded in a block of epoxid resin (He-BB-Ar-40).

The specimen is dorsally and ventrally clearly visible, without a frequently occurring white incrustation (German: Verlumung). Antennae and legs are complete, the latter are bent ventrally.

Diagnosis.

Species of larger size (9.2 mm) with long antennae, which are beset with tubercles bearing stiff bristles. Lateral margins of pronotum angulate and serrate, constricted anterolaterally. Abdomen widely rounded, connecting vein M-Cu of corium situated posterior to A-Cu.

Description.

Macropterous female. Body with fine granulation. Colour light brown with darker patches on head, pronotum and hemelytra.

Head. Wider across eyes than long (32 / 29). Clypeus subparallel, twice as long as antennal segment I, apex rounded. Antenniferous tubercles subparallel, acute, shorter than antennal segment I. Lateral margins begranulate, a distinct preocular tubercle present. Antennae slender, 1.72 × as long as width of head; antennal segment I short but widest, here secondarily depressed; II longest, thinner at middle than at its ends; III shorter than II tapering toward base; IV shortest with pilose apex. Relative length of antennal segments I / II / III / IV = 6 / 23 / 17 / 11. Eyes reniform, large, protruding laterally. Postocular lobes rounded, their margins beset with some larger tubercles. Vertex with U-shaped depression. Rostrum arising from an open atrium, four-segmented, reaching anterior 1/3 of prosternum.

Pronotum. 2.56 × as wide as long (64 / 25). Lateral margins irregularly serrate, angularly expanded at middle then strongly converging and constricted anteriorly. Anterolateral angles rectangular, anterior margin straight. Surface only slightly convex, with 4 longitudinal carinae, the median ones of full length, the lateral ones shorter, reaching to shallow transverse impressions. Humeral angles slightly carinate. Posterior margin concave at middle, rounded laterally.

Scutellum. Triangular, 1.60 × as long as wide at base (40 / 25). Lateral margins straight and carinate, apex narrowly rounded. Disk elevated at basal 1/3, surface granulate.

Hemelytra. Basal lateral expansion of corium rounded; posterior angle of corium reaching posterior margin of dorsal external laterotergite (deltg) V. Veins distinct, M-Cu situated posterior to A-Cu. Membrane with 4 distinct veins, reaching to anterior margin of tergit VII, surface wrinkled.

Abdomen. Widely rounded; lateral margins of deltg II-VI slightly convex posteroexterior angles not produced; deltg VII broadly rounded posteriorly, paratergites VIII cleft at middle, apex rounded with a blunt lateral tooth. Ventral side with a longitudinal groove, reaching from sternite VIII to prosternum. Spiracles II-VII ventral and far from lateral margin, VIII lateral and visible from above.

Legs. Femora fusiform, trochanters fused along visible sutures. Tibiae cylindrical, slender, protibial comb present. Tarsi two segmented with slender curved claws lacking pulvilli.

Measurements. Length 9.2 mm; length of antennae 2.25 mm; width of abdomen 5.05 mm; width of corium 3.75 mm; width of tergite VIII 1.7 mm.

Etymology.

The epithet refers to its unusual large size, from “macros” <Greek> large and “soma” <Greek> body.

Figures

Figures 1 - 4. Aradus macrosomus sp. n., 1 - dorsal view; 2 - ventral view; 3 - head and pronotum, dorsal view; 4 - terminal segments, ventral view.